The present invention is useful in particular, but not exclusively, for temporary installation in the piping system of a new building for the purpose of testing the plumbing system.
In the construction of a plumbing system within a new building, or when piping is added to any existing plumbing system, the authority having jurisdiction will require the plumbing system to be tested. This testing is intended to ensure that the plumbing system is leak free. In multi-storey buildings, it is necessary to test the plumbing system in vertical sections, usually covering four or five floors at once.
The usual procedure is to install a “Y” fitting at a lower end of a vertical section of the plumbing system being tested. The branch of the “Y” fitting is normally capped. When the plumbers wish to test the piping section directly above the “Y” fitting, they install an inflatable plug into the pipe through the “Y” fitting into the pipe and inflate the plug to provide a fluid-tight seal below the “Y” and the branch of the “Y” fitting.
The plumber then fills the piping above the inflatable plug with water, usually from the top or the next “Y” connection above. If the test is successful, the plumber then deflates the plug and removes it from the pipe, thus allowing test water to escape down into the downstream sewer piping within the building. The “Y” fitting piece is then capped and left in position, never to be used again, or may be removed with some difficultly and replaced by a section of pipe.
This method of testing is unreliable, since the inflatable plug tends to leak its air charge. Also, the positioning of the inflatable plug to maintain the test without leakage inside the pipe and/or out of the “Y” fitting branch connection can be difficult due to the plug length and varying piping arrangements. If the plumber decides to remove the test “Y” after testing, the result is a time-consuming procedure, due to the closeness of the adjacent piping ends, the weight of the pipe on the “Y” and the manipulation of the mechanical joint clamps required in order to allow removal of “Y” fitting. This method is also costly, because the plumber must purchase the “Y” fitting and its cap, or spend a difficult time removing the fitting and its cap for reuse, and must also purchase an inflatable plug to block the pipe and branch of the “Y”, as well as a tool to inflate the plug.
Another plumbing testing device in use at the present time is a so-called “dumbbell”, which has a pair of pipe sections connected by a central tube provided with a valve, the two pipe sections being at a fixed spacing from one another. In use, the dumbbell plumbing resting device is installed between two pipe ends of the piping to be tested and is sealed to these two pipe ends by mechanical joint couplings. When the testing has been completed, it is a disadvantage that this prior device is often difficult to remove from between the pipe ends and the joint couplings without damage to the device and/or the joint couplings.
In U.S. Pat. No. 4,932,241, issued Jun. 12, 1990 to Thurman J. Carmody et al., there is disclosed a test pipe for pressure testing piping systems including a main pipe section having top and bottom end portions and an internal closure preventing fluid flow therethrough. A valved first port in communication with the top end portion is connected by a bypass hose to a second port in communication with the bottom end portion. However, this prior art test pipe has the disadvantage, like the dumbbell device, that it is difficult to remove from between the pipe ends between which it is used.